Vacuum tube



Sept. 2, E941. P. EHLERT VACUUM TUBE FilledAug. 17,*1'938 INVENTOR. PAUL EHL ERT ATTORNEY.AA

K d h MX M\ Patented Sept. 2, 1941 lrif-*ics VACUUM TUBE Paul Ehlert, Berlin, Germany, assignor to Telefunken Gesellschaft fr Drahtlose Telegraphie rn. b. H., Berlin, Germany, a corporation of Germany Application August 17, 1938, Serial No. 225,387 In Germany September 9, 1.937

s claims. (ci. 25o-27.5)

The present invention relates to a cooling system yfor4 water cooled tubes and more especially for the anodes of high-voltage tubes.

High power tubes, such as used in transmission stations, for instance, as oscillation generator,

' power amplier, or detector, require an artificial cooling of the anode and in case of very large tubes also the cathode requires cooling. 'I'he cooling is ordinarily obtained by a cooling water current whereby pure water and preferably distilled water is caused to circulate and after having been heated in the tubes is reduced to a lower temperature in re-cooling installations. The design of such a cooling system in the hitherto customary manner generally comprises a tube having a water-cooled anode. Care is next to be taken to prevent high-frequency from leaking into the cooling line. To this end, the water is passed through insulation tubes directly ahead.

and after the power tube. Ordinarily, ceramic bodies are employed containing at the same time the channels for the supply and return line. When using distilled water and a tube having an open width of twenty millimeters, the insulating path is to be about one meter in length in order that it will act as high frequency choke. To this insulating path, a copper tube having a thick wall is connected. Since the plate potential is 10-20 kilovolts, a direct current resistor is to be interconnected in the cooling water line, the potential being consumed in this resistor. To this end, the water is to be carried in insulation channels having a length of about ten meters. These channels are wound hoses or single flow-or double ow cooling drums of ceramic material, in which the cooling water is guided in a screw line to the extent of providing the required length of the insulation path. For the protection against corrosion, an electrclytic protection layer is provided. The cooling drums again have a copper tube line connected thereto which can be directly grounded and contains the various auxiliary units. In discharge tubes of lower power two or a. greater number of tubes can be interconnected in series in the cooling water current. Tubes of very high power have also the cathode cooled, so that the latter is to be interconnected in the cooling water circulation system.

In accordance with the present invention, as shown by the drawing, there is employed as water cooling line between the electrodes I and I2 of the discharge tube and the main distribution line 1 or up to the cooling water container I3 or up to the pump I4, tubes 5 composed of ceramic material.

This measure entails a substantial rearrangement ofthe entire cooling system. In the iirst place, the comparatively large and expensive cooling water drums mentionedv above can be dispensed with. Hose drums involve the danger that the hose may burst whereby the outflowing water jet which carries a voltage may cause damage. Ceramic cooling drums require much space and represent a formed piece which is difficult of production and therefore expensive. Moreover, the cooling drums represent a notable resistance against flow of the circulating water entailing a necessary increase of the power of the pump. The subject matter of the present invention can be looked upon as a drawing out of the water channel which is generally wound on the drum. A total insulating tube length of 10 meters suicient for destroying the usual high voltages can in practice always be accommodated so that the resistance path in the water necessary for destroyingthe direct potential drop is also provided at the shortest connection of the discharge tube with the cooling water container I3 or with the pump I4. Since in reality the water paths are yet substantially longer, the water resistance is correspondingly higher and the loss in direct current essentially lower than in the hitherto customary cooling systems. It may at the most still be necessary to arrange between two tubes (see connection of the tubes II) a line loop 5 so as to obtain also .at this place the required total insulation length.

Insulation tubes are produced for the ow in one direction or in both directions .and in the latter case the supply and return line can be accommodated in the same tube body. The tubes are made in short lengths of a few meters and connected to each other in the known manner by means of ttings I5 and IB which may likewise consist of ceramic material. It is advisable that also other parts of the water circulation system are formed of ceramic masses such as, for instance, the sieve or filter arrangement designated by 8 serving for the mechanical cleaning of the cooling water. The other mountings, f1ttings, etc., such as for instance, the closing valves It, are formed suitably of a light metal alloy protected against wear and corrosion by treatment. The use of light weight metal for the fittings is particularly advisable since in case of a freely suspended insulation line, these ttings do not cause a substantial increase in weight. For the sake of uniformity, also the water for cooling the cathode I 2 will preferably be also passed through insulation tubes 6 assuring a safe protection against high frequency losses. The other various units comprise a thermometer 9, sieve or filter 8.

What is claimed is:

1. In a cooling system for high voltage transmitting tubes having at least an anode and a cathode electrode, a source of water supply, a Water cooling chamber for said anode, an inlet and an outlet fluid system connected to said water cooling chamber, a pump connected to said source of Water supply, means for fluid communication between said pump and said water cooling chamber, said means comprising straight insulating tubes of ceramic material forming substantially the entire water path from the tube cooling chamber to said pump, and means including insulating tubes connected with said water supply to cool said cathode.

2. In a cooling system for high voltage transmitting tubes having at least an anode and a cathode electrode, a source of water supply, a Water cooling chamber for said anode, an inlet and an outlet fluid system connected to said water cooling chamber, a pump connected to said source of water supply, means for fluid communication between said pump and said water cooling chamber, said means comprising a pair of straight insulating tubes of ceramic material forming substantially the entire water path from the cooling chamber to said pump, and means including insulating tubes connecting said water supply to cool said cathode.

.3. In a cooling system for high voltage transmitting tubes having at least an anode and a cathode electrode, a source of Water supply, a water cooling chamber for said anode, an inlet and an outlet fluid system connected to said water cooling chamber, a pump connected to said source of water supply, means for fluid communication between said pump and said water cooling chamber, said means comprising a plurality of tubes of ceramic material the combined length of which is substantially ten meters long forming substantially the entire water path from the tube cooling chamber to said pump, and means including insulating tubes connecting said water supply to said cathode.

4. In a cooling system for high voltage transmitting tubes having at least an anode and a cathode electrode, a source of water supply, a water cooling chamber for said anode, an inlet and an outlet fluid system connected to said water cooling chamber, a pump connected to said source of Water supply, means for uid communication between said pump and said water cooling chamber, said means comprising straight insulating tubes of ceramic material forming substantially the entire water path from the tube cooling chamber to said pump, a plurality of light weight metallic fittings for connecting said insulating tubes together, and means including said insulating tubes connecting said water cooling supply with said cathode.

5. In a water cooling system for a plurality of transmitting tubes, a source of water supply, a water cooling chamber for said tubes, an inlet and an outlet fluid connection extending between said water cooling chamber and said water supply, at least two of said transmitting tubes having a fluid line loop forming a series uid connection between said water cooling chamber and said source of water supply.

6. In a water cooling system for a plurality of transmitting tubes, a source of water supply, a water cooling chamber for said tubes, an inlet and an outlet fluid connection extending between said `water cooling chamber and said water supply, a plurality of insulating tubes interposed between said water cooling chamber and said source of water supply, at least two of said transmitting tubes having a iluid line loop forming a series uid connection between said water cooling chamber and said source of water supply.

PAUL EHLERT. 

